Auto update stock of books

Hi,
I have attached a file where I am updating the books library in excel. Here there are total 3 sheets. In Sheet 1 & 2 I am putting the data manually. Sheet 1 is the inventory which updating the books purchase details and Sheet 2 is Issue register where I am putting the details to whom the books issued. In Sheet 3 is the Stock sheet where I need the stock of the books in D column. This will check the 2nd sheet and if the particular book is not issued / issued and accordingly it will update. If any new book purchased or any existing book purchased another copy that also added in this stock sheet. If books issued and not came then it will not count in stock and after received the book this will added in stock. Request your help.